Not quite. The real question is why are these adjuncts being paid so little? It could be that for many adjuncts the desire to be there forces them to accept whatever pay. It could be a desire to teach for the sake of it or it could be a lack of options. But also, why do colleges pay their student facing employees so little? They probably don’t have incentive to increase pay and they deginitely want to cut costs.

This is why they want to unionize. Ironically, the tenure track and tenured professors are unionized as part of that institution's academic senate. Adjunct professorships probably arose out of the "postdoc" path, as well as being an academic association for industry collaborators. So temporary in nature. But the reality is different. Better off teaching K-12 at least they have a union.

It could be that unionization keeping pay down or contributing to it. It makes the unionization more valuable for incombants and keeps out competition.